andyscotland

The British gypsum white book is also a good resource https://www.british-gypsum.com/specification/white-book-specification-selector/white-book-overview

It's worth confirming which part of the UK you are in as the rules are subtly different in each country. For example in Scotland as soon as there's any sort of toilet/shower etc the structure requires building warrant approval regardless of size. Not sure if that applies elsewhere.

Yeah as others have said dust and smoke alarms do not mix. If you are still doing works and want some temporary protection then you could consider heat alarms (which can be suitable for dusty environments) and then replace with smokes at the end of the project - however these take longer to detect a fire so may not be suitable if you are living/sleeping there. Otherwise you need to cap them (or remove them) any time the house is dusty and/or treat them as consumables if you're sleeping there during works and want peace of mind that you'll get early warning to evacuate overnight.

That does look relatively full to me. A 6 core cable will be even more rigid round bends I think. Also as @-rick- mentioned that does look like you're trying to pull them as one big lump, it will be much easier if you spread out the point where each one joins onto the one before so that you get as much of a taper as you can. The thinner cable will help to lead the following cable round the bends and so on. Possibly, it will have fewer snag points on bends and obviously will sit dead straight in the sections where your flexi is dropping - but you can potentially solve those without swapping it all out. Also the smooth conduit might actually have more friction along the length (the cable is in contact with the wall all the way, unlike flexi where 50% is on a ridge and 50% over a valley) so might not end up much different. For bending you don't need a heat gun (and can easily over melt it that way), just insert spring, rub up and down the outside with a rag a bit to gently warm it a little, then bend. Bend it slightly over the angle you want then you can ease it back to the exact angle as you fix it into place.

Plus the existing network cable? I agree with @-rick- that sounds quite a bit for 20mm with bends. It won't be helping if they're 4 core sheathed - you'll be losing space to the sheath and also that makes it more rigid around bends. If the whole run is in conduit between boxes you could use singles, starting each one staggered after the other as @-rick- said.

No, I think maybe you've missed mine 😁 Absolutely, kitchen should have a heat alarm. However, it is possible for cooking smoke to leave the kitchen (especially if an extractor hood is not in use) and depending on the layout and airflow in the house that can make it to a smoke alarm elsewhere (e.g. in a location where it is compliant/required such as a hallway or landing). With an interlinked system this can then cause a nuisance alarm on the whole system. I'd only got mentioned it because of @Redbeard commenting they'd had a lot of nuisance alarms on their newer interlinked system : one possible explanation is that the smoke alarms were in different locations to the old standalone ones, or that they were more sensitive/reliable than the old ones thus picking up kitchen smoke wafting around outside the kitchen.

Absolutely, but I've seen places where a smoke alarm has been mounted outside a kitchen but near enough to it (or further away but in the natural path of airflow from the kitchen through the house) that it triggers. I agree with a well designed system & correct selection/location of heads there shouldn't be an issue.

I believe they're being discontinued - possibly partly because AFAIK they don't meet the building regulations requirements as they're not certified to the relevant British Standard and interlink over WiFi so won't work if your router is on fire. Depending on the circumstances of your nuisance trips this would suggest perhaps: * The mains alarms were doing a better job of detecting actual smoke (burned toast etc) than the old battery ones. I'd say that's a benefit but might mean they weren't the right types or locations of alarms for your property. * They were mains powered but radio interlinked and perhaps not properly house coded (or from one of the cheaper brands) so picking up interference from elsewhere. * They were mains interlinked but with a fault in the interlink wiring causing unwanted triggers. I'd say interlinked alarms (from a decent manufacturer) have a lot of safety benefits over standalone ones in terms of detecting and more importantly waking the occupants in time to evacuate - especially if mains powered and wired interlinked. If you do occasionally get cooking smoke etc spilling out of the kitchen to the rest of the house then you can minimise impact of nuisance trips with a remote control to silence alarms next to the cooker (much easier than running around the house flapping a tea towel 🤣)

It can also help to do it as a two person operation - one applying fairly constant tension on the draw wire/cord (good job for a teenager if you have one 🤣) and one pushing the cable in at the other end. I've found that reduces the tendency for it to poke into a ridge on the bend rather than going round. Make sure both the push and pull are directly in line with the end of the conduit opening to at least eliminate the friction at those points.

Thanks @nod - and then Fine Surface Treatment over the filler & boards on the fermcaell sides? Will that hide the tape ok?

Hey, I am getting towards finishing (in one room at least 🤣). I have fermcaell on two external walls (part of a fire resistant buildup) and plasterboard on two internal walls and the ceiling. I'm planning to skim the plasterboard. Wondering what's the best way to fill & join the joints between the fermcaell and the PB. Should I use fermcaell joint filler and paper tape? Or normal joint filler (Easifill/Knauf/etc) and paper tape? Or...? I understand the fermcaell Fine Surface Treatment is very thin - if I use tape on the joints will it be able to cover/hide it? Or would I be better off skimming the fermcaell as well to get a neat finish? Questions questions! 🤣 Thanks!

Qcad is good for "classic" 2D CAD - open source so the main version is free forever. The "Pro" addin adds some useful features and is €41, that includes updates for a year but you can continue to use the version you have indefinitely.

My friends continue to ask "is your extension finished yet" but have now learned to accept a simple "nope 🤣" rather than an explanation of where I'm at/what hurdle or side project or life thing has delayed it this time!

All true, although also this was more of an issue before RCD protection on 240v supplies was available/common. Obviously still inherently safer if the voltage to earth can only ever be 55V, as you're already in a safe state rather than relying on a device to operate. The other side benefit of 110v is that they use ceeform connectors which are more robust than 13a plug/socket and can be waterproof etc for use outdoors. However you can just as easily run 240v on ceeform if you choose. I'd agree, in the past 110 was very common when your options were mains or hand power. But much more common to see battery tools now. Also any trades that do have 110v tools will also almost certainly have their own standalone 110 transformer in the van. So long as there is a mains supply they can access, they can pop their own transformer there, run their own 110v cable to where they're working, and crack on. So I'd suggest in the first instance: - check which if any of your trades are going to use mains (110v or 240v) tools and if so where, and if they actually need you to provide a 110v supply. - if people are likely to need to temporarily run power from a mains socket to somewhere else on site, perhaps invest in some brightly coloured 16A cables (this kind of thing, camping/caravanning or theatre/event suppliers will have loads of options) with adaptors to/from 13A to allow them to do so safely.

@Onoff is correct on the official manufacturer's instructions, normally it would be toothed side to the box (point 1 on the instructions) - the idea is that bites in so you tighten by rotating the gland body. On a metal box, that is part of getting a good earth connection (through the biting teeth) between the nut and box body. However, on a plastic box that obviously isn't an issue - it just needs to be screwed tight enough to get a solid mechanical connection. As you've already glanded the cable, you won't be able to rotate the gland and there's no benefit to undoing that - so put the smooth side to the wall and tighten the nut, as per point 3 on those instructions.

Personally, yes I would go Wago box below the cabinet (assuming that's where the ring wiring is accessible). Although technically you could get back to it, it will be out of sight and a pain in the backside so a maintenance free junction makes a lot more sense than a socket.

We have some plates & bowls that get extremely hot in the microwave. Not a scientist, but I suspect either there is some water molecules trapped in the ceramic that weren't removed when the clay was fired, or there's some sort of metallic particles in the ceramic or the glaze that are reacting to the electromagnetic field.

Ah yeah that sounds much more faffy than actual Wago. Especially for stranded.

Indeed. I don't know for sure, but from idle curiosity when on holiday they seem fairly similar, but usually with more ways (even small ski apartments tended to have a board more like the kind of thing you'd see on industrial/commercial installs here with sockets divided into multiple radials where UK practice would usually be 1 or perhaps 2 rings for a 3 room flat). My hunch would be they essentially run the same cabling but instead of joining at the furthest point it becomes two radials at the CU. Indeed - although as well as the ring itself the other factor is (in normal domestic with gas heating) it's not that common for a ring to be loaded up to the full 32A for any length of time, if it complies with the floor area & outlet type restrictions. Especially considering that even if the ring is broken the sockets are still split between two cables (assuming you're not unlucky enough to get a break between CU and first socket). In fact that is the basis on which the regs allow the oversized protective device for the cable, rather than the ring per se. One way to think of it is the places you're allowed to use a ring would also be suitable for 1 or 2 20A radials without any concerns that they'd be constantly tripping. So although the ring is protected at 32A, most of the time the current will be below the 20A rating of the cable. The extra 12A just provides a bit of an extra buffer for short-lived concurrent loads. That said, I prefer radials for new work.

I am not a lawyer, and CIL is obviously something where you want to be extremely careful. However, it seems to me that "letting out of a whole dwelling" would (for other legislation) normally mean situations where the property ceases to be your only/main home e.g. you move out and take tenants. An Airbnb-style temporary arrangement where you charge people to share your home (even if you happen to be on holiday at the time) might not be the same thing. I wouldn't take any risks but if the money is significant to you it might be worth getting professional advice or asking the council for an exact interpretation of that clause before writing off the idea.

Is the internal circuit a ring main, or something else? Is there a fused spur unit where it connects to the internal circuit, or is it just connected to the back of a socket / a junction box etc? If it's connected direct (e.g. it is an "unfused spur") then it should be wired in the same size cable as the rest of the circuit (likely 2.5mm²) but it can only serve a single point (single socket/double socket/light).

The cable sizing partly depends on where/how the circuit is supplied from and the sizing of the protective device. Is this direct from the consumer unit or a fused/unfused spur from something else? I assume the circuit already has RCD protection (wasn't always provided for exterior lights in the old days but definitely required for a socket).

Indeed. I think they've invented that requirement (or are repeating from a scheme provider who have invented it). Neither BS7671 or the On Site Guide specify any limit on the number of unfused spurs connected to a single outlet. The only stated limit is for outlets on a spur. The only factor would be the requirement (only present in the On Site Guide) not to have more unfused spurs than outlets/appliances actually in the ring. And of course the capacity of the outlet terminals as @Nickfromwales said. Spurs on ring finals are a bit of a historical anomaly. Despite being ubiquitous in the UK, until the 17th edition these circuits were barely covered in 7671 itself, and only detailed in the On Site Guide. The OSG is basically just there to save everyone having to work from first principles (and make mistakes). The overall requirement is that the circuit is not likely to be overloaded for a significant period and that load is reasonably distributed around the ring. This is what allows using a cable that is technically undersized for the protective device (in fact a little overheating helps by increasing resistance and sending some current down the other leg of the ring). However since there is no requirement for any particular spacing between outlets, you could without question have two double sockets or two junction boxes beside each other and a spur off each one. Taking two spurs from one socket is essentially identical electrically - arguably better, since there are fewer sockets overall at that point in the ring. But it does depend on a little common sense about expected use. If you want to plug in 6 phone chargers and laptops, no problem. If you're needing to plug in 6 kettles then that might not be the best circuit design.

Interesting... I wonder when that changed. Certainly after I trained (which was a while ago, though well after the new colours were introduced). Very helpful to know though!

Old fashioned screw terminals have been around a long time and if properly installed are fine, there are millions of houses using them. That said, I am a huge convert to Wago (lever-style) and similar connectors. They make it much easier to get a reliable long-term connection at the full current carrying capacity of the conductor, and eliminate a whole class of potential issues. And (unlike screw terminals, which can work loose over time) do not require future inspection/maintenance.